Missisquoi Bay Lake
Franklin County, VermontView mapDirections
Vermont DEC publishes the water-quality measurements for Missisquoi Bay Lake. Here is what has been measured.
- Eutrophic
- Impaired · Mercury
- Public access
Missisquoi Bay Lake in Franklin County, Vermont has water-quality measurements published by Vermont DEC, shown here as reported. Water clarity: 5.6 ft visibility. Phosphorus: 42.8 µg/L. Chlorophyll-a (algae): 12.1 µg/L.
Missisquoi Bay Lake is a productive, nutrient-rich eutrophic lake in Franklin County, Vermont. Limited fish-species data available. Public access is available with 3 public boat landings. Compared to the 4 other monitored lakes in Franklin County, Missisquoi Bay Lake ranks #3 for water quality.
Source: EPA Water Quality Portal sampling records, VT DEC, last sampled 2025-08-08. Methodology: how these readings are compared.
What Missisquoi Bay Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch3 documented ramps
Swimming conditions
Readings onlyRecreation use not supported
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Missisquoi Bay Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury, nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether Missisquoi Bay Lake is safe to swim in today is a call for the Vermont Department of Environmental Conservation and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Missisquoi Bay Lake
These are the measurements Vermont DEC publishes for Missisquoi Bay Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Murky, only visible to about 5.6 ft. Phosphorus 42.8 µg/L. Chlorophyll-a 12.1 µg/L. TSI 55.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 5.6ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 42.8µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 12.1µg/L | Poor GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 55 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Missisquoi Bay Lake
Answers come straight from the public measurements and survey records on this page.
Recreation & Access
- Rock RiverPublic
- Larry GreenePublic
- Campbells Bay CampgroundSemi-private
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Missisquoi Bay Lake
Compare lakeside cabins, hotels, and vacation rentals near Missisquoi Bay Lake in Franklin County, Vermont — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water. The water-quality readings cover nutrients and algae, not lodging. Cabins and rentals around Missisquoi Bay Lake are listed below.
Top-rated places to stay near Missisquoi Bay Lake
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Fishing Missisquoi Bay Lake
EPA Impairment Status
Missisquoi Bay Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 4A).
Causes of impairment
Designated uses not supporting: Fish consumption, Recreation, Other.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit VT05-01L01_01 · Official waterbody report
Nearby Lakes in Franklin County
Frequently asked questions about Missisquoi Bay Lake
Where is Missisquoi Bay Lake?
- Missisquoi Bay Lake is a lake in Franklin County, Vermont. Its water-quality measurements are published by Vermont DEC and shown on this page as reported.
What is the water quality of Missisquoi Bay Lake?
- Missisquoi Bay Lake in Franklin County, Vermont has water-quality measurements published by Vermont DEC, shown here as reported. Water clarity: 5.6 ft visibility. Phosphorus: 42.8 µg/L. Chlorophyll-a (algae): 12.1 µg/L.
Is Missisquoi Bay Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Missisquoi Bay Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury, nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Are there boat ramps on Missisquoi Bay Lake?
- Missisquoi Bay Lake has 3 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Rock River, Larry Greene, Campbells Bay Campground. Public access is listed as yes.
Can I fish at Missisquoi Bay Lake?
- Missisquoi Bay Lake has 3 documented boat landings in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Vermont's fish and wildlife agency, so check its current regulations before you go.
Explore Missisquoi Bay Lake across LakeQuality
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Where this data comes from
266 measurements from 2 monitoring stations, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Vermont Dept of Environmental Conservation
1VTDECWQ266 samples · 2020–2025
Analytical methods
- EPA approved Alternate Test Procedure for 4500 P H. Has a 28 day hold without acid preservation.
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
- 2130 B ~ Nephelometric Method
Monitoring station identifiers (2)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Named boat-access points from the USGS National Boat Ramps inventory